Control systems responsive to the passage of a body



Jan.- 13, 1970 K. COOPER' 3,439,460

CONTROL SYSTEMS RESPONSIVE TO THE PASSAGE OF A BODY Filed May 27, 1968 2 Sheets-Sheet 1 KEN N ET H e b PER INVENTOR:

K. COOPER 3,489, 60

CONTROL SYSTEMS RESPONSIVE TO THE PASSAGE OF A BODY Jan. 13, 1970 2 Sheets-Sheet 2 Filed May 27, 1968 INVENTOR:

m W in w I c mm mm Em m \M 5 0V QM, N m AM 2 F 2 m mv lmwm Om K WV WW \W l wvv WW Wm JfiMW N NWWW, WW WW NW NW \W OW WNQM W\ N\ .W\ m\ Vi M! W\ O\ mmw w mm mi sm m lm MW -TT m V W WM QI w \r WV U Tlnited States Patent 3,489,460 CONTROL SYSTEMS RESPONSIVE TO THE PASSAGE OF A BODY Kenneth Cooper, Orrell, near Wigan, England, assignor to Gullick Limited, Wigan, Lancashire, England, a British company Filed May 27, 1968, Ser. No. 732,259 Claims priority, application Great Britain, June 8, 1967, 26,493/ 67 Int. Cl. E21c 1/00 US. Cl. 299-1 10 Claims ABSTRACT OF THE DISCLOSURE A control system responsive to the passage of a body comprises control means and two magnets which are arranged by mutual repulsion to operate said control means when brought into proximity, one of said magnets being on the body so that it is brought into proximity with the other magnet during passage of said body. The system is particularly applicable to a mineral mining system, the control means controlling the advance of a coal face conveyor and/ or mine roof supports as working of the mineral face proceeds by passage of a mineral mining machine along the length of the conveyor. One of said magnets is mounted on the mineral mining machine and there are a plurality of said control means, for the conveyor advancing means and/ or the mine roof support advancing means, spaced apart along the length of the mineral face so that they are operated in turn by the passage of the mineral mining machine along the mineral face.

This invention is for improvements in or relating to control systems responsive to the passage of a body.

One particular application of the invention, which is mentioned by way of example only, is to a control system, for controlling the pushing-over or advancing section by section of a coal face conveyor, which is responsive to the passage of a mineral (e.g. coal) winning or cutting machine.

It is now a common practice to push over or snake forward a coal face conveyor progressively behind the coal winning machine, which may ride on the conveyor, by means of pressure-fluid (e.g. hydraulic) rams. These rams may be embodied, for example, in self-advancing mine roof supports the rams, if they are double-acting, serving in the well known way to advance both the conveyor and the supports towards the newly exposed coal face.

It is convenient and advantageous to arrange for the mineral winning machine, as it passes along the mineral face and ploughs or otherwise delivers mineral into the conveyor, to control the snaking or pushing forward of the sections of the conveyor behind it. One object of the present invention is to provide an improved arrangement of this character which avoids the necessity for any physical contact between the machine and the control means but which, at the same time, is robust and not readily rendered inoperative or operated accidentally having regard to the conditions which exist in a coal mine.

According to the present invention there is provided a control system, responsive to the passage of a body, comprising control means and two magnets which are arranged by mutual repulsion to operate said control means when brought into proximity, one of said magnets being on the body so that it is brought into proximity J 3,489,460 Patented Jan. 13, 1970 of non-magnetized but magnetic material into its vicinity is avoided. This is important in the case of, for example, a coal mine where miners may be walking along the coal face carrying a shovel or other implement.

The control means may comprise two control devices one of which is operated when the body travels in one direction and the other when it travels in the opposite direction. One control device has a north pole magnet and the other a south pole magnet exposed to the pathway of the body. The magnet on the body is then mounted so that it can be moved to expose a north pole to the magnets of the control means when the body passes in one direction and a south pole when the body travels in the opposite direction. Thus, during passage in one direction one control device will be operated and during passage in the opposite direction the other control device will be operated.

One particular embodiment of the invention will now be described, by way of example, as applied to a control system for the pushing or snaking over of a coal face or like conveyor. In the following description reference is made' to the accompanying drawing in which:

FIGURE 1 is a perspective view of equipment at the coal face including roof supports, conveyor and coal winning machine,

FIGURE 2 is a diagram of the control system, and

'FIGURE 3 shows, semi-diagrammatically, one of the several identical control means incorporated in the system.

The roof support arrangement with which the system about to be described is associated comprises a plurality of hydraulic, self-advancing roof supports, of known construction, spaced apart along the coal face F in the usual way. Some of these are shown in FIGURES 1 and 2 and are numbered to 28 inclusive. The articulated, coal face conveyor C is located between these roof supports and the coal face F and the coal cutting machine M runs on and along and is guided by the conveyor as it traverses the face in opposite direction, coal being removed from the face at each traverse and deposited into the conveyor.

As the machine travels along the face the conveyor is snaked or advanced section by section, towards the newly exposed mineral face ready for the machine M to make its next journey in the opposite direction.

Each of the roof supports has a hydraulic ram 29 for advancing it in the well known way, using the conveyor C as an anchorage, the ram being connected to the conveyor as indicated at 30.

In the arrangement shown in FIGURE 2 the hydraulic ram 29 of each fourth support, namely, the supports 10, 14, 18, 22 and 26, is double-acting so that it serves not only to advance its support but also to snake or advance the conveyor.

The operation of these double-acting rams is controlled by the passage of the coal cutting machine M through the control means, shown in FIGURE 3, which comprises normally open valve devices 31 and 32 having ports 33-, 34 and 35 connected in a fluidic system of known kind in which pneumatically-operated valves are controlled by pneumatic impulses.

The ports 35 are exhaust ports and are adapted to be closed, as hereinafter described, by valve members 36 pivotally supported at 37 and having spring means 38 urging them to the open position.

The valve member 36 of the valve 31 has a magnet 39 attached to it which is positioned so that its north pole (N) faces the coal face F.

The valve member 36 of the valve 32 has a magnet 40 attached to it which is positioned so that its south pole (S) faces towards the coal face.

The ports 33 of the valve devices 31 and 32 are air supply ports and the ports 34 are connected respectively to fluidic flip-flops 41 and 42 of the fluidic system. The

3 flip-flops have ports 43 and 44 and control a supply of compressed air for the operation of hydraulic valves 45 (see FIGURE 1) controlling the operation of the conveyor advancing rams 29.

The valves 31 and 32 are connected to the fluidic flipfiops 41 and 42 by pipes 46 and the flip-flops are connected to the hydraulic valves 45 by pipes 47 and 48.

The non-physical operative connection between the coal cutting machine M and the valves 31 and 32 comprises a magnet 49 pivoted at 50 on the coal cutting machine. This magnet can be turned and set so that either its north pole (N) or its south pole (S) faces the magnets 39 and 40'of the valves 31 and 32.

It should be understood that there are flipflops 41 and 42 for each of the sets of valve devices 31, 32, only those associated with the supports and 26 being shown in FIGURE 2.

The system above described operates as follows:

Assuming (see FIGURE 2) that the coal cutting machine is traversing the coal face from left to right and is passing the support 18 and the magnet 49, on the machine, has been set so that its north pole faces the valves 31 and 32. As the magnet 49 passes the valve 31 it will repel the magnet 39 and close the port 35 of the valve 31. As a result, a fiuidic (pneumatic) impulse will be transmitted to the flip-flop 41 and the hydraulic ram associated with support 10 will be operated to push over a section of the conveyor C. Thus, as the coal cutting machine traverses the face the hydraulic ram of each eighth roof support behind it will be rendered operative in turn to push over or advance a section of the conveyor.

It will be appreciated that as the magnet 49 passes the magnet 40 of the valv 32 it will not operate said valve because the valves are adapted to operate only by repulsion between the magnets and when the coal cutting machine is travelling from left to right the north pole of the magnet 49 will face the south pole of the magnet 40.

Before the coal cutting machine commences its traverse along the coal face from right to left the magnet 49 is turned so that its south pole faces the magnets 39 and 40 of the valves 31 and 32. Thus, for this direction of traverse, the valves 32 will be operated (closed) but not the valves 31. The valves 32 will in turn cause operation of the flip-flops 42 so that again the hydraulic rams of each eighth support behind the machine will be operated in turn to push over or advance sections of the conveyor behind the machine.

It will be understood that the valves 31 and 32 could be replaced by electric switches and/or the flip-flops 41 and 42 by electrical or electronic switch means controlling solenoid valves of the hydraulic conveyor advancing rams, i.e. the pneumatically-operated valves 45 would be replaced by magnetically-operated valves which control the supply of hydraulic pressure-fluid to the rams. In other words, the system may be wholly fiuidic, except for the magnets 39, 40 and 49, wholly electric or electronic or a combination of both electric or electronic and fluidic.

Instead of, or in addition to controlling the advancing of the conveyor, a system as above described could be used to control the advance of the roof supports by the passage of the mineral mining machine. For instance, where the control means are positioned at every fourth support, as shown in FIGURE 2, the system described may control the operation of the double-acting advancing rarn provided in each such fourth support, i.e. in the supports 10, 14, 18, 22, 26 and so on. As each of these supports has almost completed its advance it may be caused to operate valve means which cause the next support (e.g. support 11) to advance and this support in turn operates valve means to cause the next support to advance and so on until the three supports (e.g. the supports 11, 12 and 13) between those having a control means 31, 32, have been advanced. Such an arrangement whereby one support when advanced is caused to start the advance of 4 another is described in the specification of our British Patent No. 1,038,262.

I claim:

1. A control system responsive to the passage of a body, comprising control means and two magnets operative by mutual repulsion to operate said control means when brought into proximity, one of said magnets being on the body so that it is brought into proximity with the other magnet during passage of said body, said control means being duplicated, one control means having a magnet With its north pole directed towards the path of movement of the body and the other control means having a magnet with its south pole directed towards said path of movement of the body, the magnet on the body being movable so that either its north pole or its south pole can be directed towards the magnets of the two control means whereby said control means can be caused to operate selectively.

2. A control system as claimed in claim 1 wherein the control means is a fluid flow control valve.

3. A control system as claimed in claim 1 wherein the control means is an electronic or electric switch.

4. A control system as claimed in claim 1 wherein the magnet on the body is pivotally attached thereto so that its north or its south pole can be directed towards the magnets of the two control means.

5. A control system as claimed in claim 1 wherein the control means is a fluid flow control valve connected to and arranged to operate a fluidic flip-flop in a fluidic control system.

6. A control system as claimed in claim 5 wherein the fiuid flow control valve has a through passage, one end of which has a fluid inlet port and the other a fluid exhaust port and a further passage connected to said through passage and to said fiuidic flip-flop for the operation thereof, the exhaust port having a normally open valve member provided with one of said magnets so that it is closed by the passage of the body whereby a fiuidic impulse or signal is sent to the flip-flop.

7. The combination of a mineral mining machine, a mineral face conveyor, means for advancing said eonveyor towards the mineral face as the latter is worked by the mineral mining machine and a system for controlling the operation of said conveyor advancing means in response to movement of the mineral mining machine along the mineral face, said system comprising plural control means, for the conveyor advancing means, spaced apart along the length of the conveyor, each control means having a magnet and the mineral mining machine having a magnet which is brought into proximity with said magnets of the control means as the mineral mining machine moves along the conveyor, said magnets of the control means and the magnet of the mineral mining machine being arranged by mutual repulsion to operate said control means whereby the conveyor is advanced or snaked towards the mineral face in sections or stage-by-stage behind the mineral mining machine.

8. The combination claimed in claim 7 wherein there are substantially identical pairs of said control means spaced apart along the length of the conveyor, one control means of each pair having a magnet with its north pole directed towards the path of movement of the mineral mining machine and the other control means of said pair having a magnet with its south pole directed towards said path of movement of the mineral mining machine, the magnet on the mineral mining machine being movable so that either its north pole or its south pole can be directed towards the magnets of the pairs of control means whereby one or the other control means of each pair can be caused to operate selectively.

9. The combination of self-advancing mine roof supports, a mineral mining machine adapted to work a mineral face in advance of said supports and a system for controlling the operation of the support advancing means in response to movement of the mineral mining machine along the mineral face, said system comprising plural control means for the support advancing means spaced apart along the length of the mineral face, each control means having a magnet and the mineral mining machine having a magnet which is brought into proximity with said magnets of the control means as the mineral mining machine moves along the mineral face, said magnets of the control means and the magnet of the mineral mining machine being arranged by mutual repulsion to operate said control means whereby the supports are advanced towards the mineral face behind the mineral mining machine.

10. The combination claimed in claim 9 wherein there are substantially identical pairs of said control means spaced apart along the length of the mineral face, one control means of each pair having a magnet with its north pole directed towards the path of movement of the mineral mining machine and the other control means of said pair having a magnet with its south pole directed towards said path of movement of the mineral mining machine,

the magnet on the mineral mining machine being movable so that either its north pole or its south pole can be directed towards the magnets of the pairs of control means whereby one or the other control means of each pair can be caused to operate selectively.

References Cited UNITED STATES PATENTS ERNEST R. PURSER, Primary Examiner US. Cl. X.R. 6l45.2; 251- 

